As graduate students studying philosophy at Rutgers University, they earn no more than $20,000 a year. But they consider themselves well-off when compared with the vast majority of people in the rest of the world.

The three are giving away a chunk of what they earn now and have pledged to give a heftier chunk after they graduate and embark on careers.

"Even people without a lot of material wealth can make a huge impact on those less fortunate, if they give to the right places," Lee told msnbc.com via e-mail.

"If everyone who considered his income 'ordinary' decided not to give, many of the most important causes could go unfunded," Beckstead added, also by e-mail. "Moreover, people of even modest income can make a significant difference in the lives of large numbers of people if they give a portion of their income to the right charities."

Three of every four adult Americans plan to give money to charity between Thanksgiving and the end of the year, according to a survey commissioned by Convio, a fundraising software company. The average total gift is expected to be $281.

But it's not just money that can make a difference. Extraordinary acts of giving by ordinary people can make a profound difference in — and in some cases save — other people's lives.

Here are some of those stories:

Giving What We CanBeckstead, Lee and Campbell, all in their mid-20s, are among a group of Rutgers students who are launching the first U.S. chapter of Giving What We Can, a U.K.-based international charity movement dedicated to eliminating poverty around the world. The initiative was started by Toby Ord, an ethics researcher at Oxford University.

Participants pledge to give at least 10 percent of their incomes to wherever they think it will do the most to relieve suffering in the developing world.

Lee and Beckstead have pledged to give away all income beyond their stipends until graduation and half of their post-tax income from then until they retire. Campbell has pledged to give away 5 percent of his income for now, and more after he receives his Ph.D. and starts his career.

"I grew up in an upper middle-class family in Woodbury, Minn., and did my undergrad at the University of Minnesota. While my parents are not rich by national standards, I do consider my upbringing privileged from a global point of view, as should most Americans," Beckstead told msnbc.com. "Someone who earns even a modest income by U.S. standards is quite rich; making even $25,000 a year puts you in the top 3 percent of the world's wage earners."

Campbell, originally from Ann Arbor, Mich., said he began donating to charity after reading Peter Unger’s book "Living High and Letting Die" as an undergraduate. "It is amazing that, even with a modest income of $20,000 per year, one can be in the richest 5 percent of the world’s population," he said by e-mail.

Lee, a Canadian who plans to get a master's in philosophy before going on to law school and becoming a corporate lawyer, grew up in Toronto in a middle-class household. He says people with an "average" U.S. salary can save hundreds of lives.

"This holiday season, I ask that we think deeply about the importance of giving in our lives," Lee said. "Giving need not be seasonal. It need not be something to do only after you've gotten everything you want for yourself. It is something we can do for our neighbours, be they next door or overseas, at any time we wish, and that will make a huge difference in their lives."

Beckstead, a Ph.D. student who hopes to become a philosophy professor, figures he can live comfortably on half of whatever his take-home pay is after he graduates. "The things I enjoy most — spending time with my girlfriend, my friends and my family; enjoying nature; reading interesting books — do not cost much money at all," he said.

A stranger's kidney, a boy's lifeTwo-year-old Nathan Saavedra is celebrating Christmas with a new, healthy kidney — thanks to the generosity of a stranger.

The Carpentersville, Ill., toddler suffers from "Prune Belly Syndrome," a rare birth defect that causes the skin of the belly area to wrinkle like a prune, leading to urinary tract problems.

Without a new kidney, Nathan would have faced continued dialysis, the risk of infections and an uncertain future.

Enter Chris Doing, a 38-year-old information technology security analyst, who first read about Nathan in the Elgin Courier-News in April. He contacted Children's Memorial Hospital, and blood tests determined he was a donor match.

On Oct. 25, doctors at one hospital removed Doing's left kidney, which was taken to another hospital and transplanted into little Nathan. Because Nathan's abdomen was distended, there was just enough room for an adult kidney. Both operations went without a hitch, and for the first time in his short life, Nathan had normal kidney function.

Doing visited Nathan and his mother, Tina Saavedra, in the hospital a week after surgery. It was the first time that Doing met the boy.

"I was really surprised at just how happy and smiling he was," Doing told msnbc.com.

"It was a very emotional meeting for his mom and I," Doing said. "I can't put it into words. Obviously, she feels a debt that she can't fathom repaying and that makes me uncomfortable, because I don’t feel like they owe me. I was just glad to help."

She said Nathan still faces future abdominal surgery and will always take anti-rejection medications, but his prognosis is excellent.

She calls Doing a hero. "I will always feel so happy to have met him and for him to have saved my son," she told NBC Chicago.

Doing, who took a week's vacation to recover from surgery, doesn't regard his gesture as an act of heroism.

"The thing I’ve learned through the whole process is how easy it is to make an impact on other people. People have reached out to me and told me it inspired them do do something for others," Doing said.

"It was honestly one of the most rewarding vacations I’ve ever taken."

An $11.2 million lottery windfall — for charityAllen and Violet Large of Lower Truro, Nova Scotia, have each other — and that's more important to them than anything money can buy.

The retired Canadian couple, both in their 70s, won $11.2 million in the Atlantic Lottery's July 14 jackpot drawing. But rather than go on a big spending spree, they decided it would be better to give it away.

The Larges — he was a welder for three decades and she worked in retail — have given the bulk of their newfound fortune to charities, hospitals and friends.

"Atlantic Canadians are known for their good will and kindness. The generosity shown by Allen and Violet Large put them in a league of their own," Atlantic Lottery officials said in a statement.

"We often see lottery winners who share their winnings with others. Family, friends and community groups all benefit, and it’s great to see lottery winnings put to good use. To our knowledge, we’ve never before seen the level of generosity of Allen and Violet. They are truly wonderful people."

"It made us feel good,” Violet Large, who recently has undergone chemotherapy for cancer, told the Halifax Chronicle-Herald. "And there’s so much good being done with that money."

"That money that we won was nothing," Allen Large told the newspaper. "We have each other."

Homeless man returns cashDave Talley surely could have used the$3,300 he found in a backpack at a light-rail station in Tempe, Ariz., in November. Instead, the homeless man tried to find the rightful owner.

Talley took the bag to an office of the Tempe Community Action Agency, which runs a system of rotating homeless shelters. An employee there found a small flash drive with files on it that contained information leading to the backpack's owner, Arizona State University student Bryan Belanger.

Turns out Belanger set down the bag while waiting for a train to arrive. He was planning to use the money to buy a used car to replace the one he wrecked in an accident the previous month, according to the Arizona Republic.

Belanger didn't hold out much hope that he would see the money again, so he was surprised when he got a call from a Community Action Agency employee. When he went to the office to pick it up, he found "not a dollar was missing," he told the newspaper.

"It's humbling and it puts things into perspective," Belanger said of Talley's decision. "From his point of view, he could've taken care of himself by paying for rent or something with that money."

Talley said he toyed with the idea of keeping the money.

"I could've done a lot of things with the money," he told the Republic, "but none of them would've been right."

Belanger said he was overwhelmed that his backpack and money were returned. “It's just the greatest thing I've ever experienced I think," he told ABC15.com. "It really is a lesson to keep your faith in people, and character exists no matter what your circumstances are."

Belanger did give Talley a cash reward. After hearing about his story, people across the country said they plan to donate money to Tally, according to ABC15.com.

Talley was honored by the city of Tempe, which recognized him for his honesty and set up an account through the city to help him out of homelessness.

Blood brothersWhat's a little competition among brothers? A lot of blood, in the case of Mark, Howard and Patrick Gaskin.

The three brothers gathered at a mobile blood donation clinic in Cambridge, Ontario, on Dec. 4 to donate blood and to celebrate middle brother Howard's 100th donation, the newspaper reported. All three also brought a son along to donate.

“One thing is the motivation, to help others; the other thing is I set a goal — I wanted to get to 100 (donations),” Howard told the Record.

“Not that I’m going to stop, because I’m not going to stop.”

Canada's system does not pay donors for the blood they give.

According to the newspaper, Howard leads the pack with 100 donations, youngest brother Patrick has 89, and eldest brother Patrick has 77.

Howard works as a director at the pharmaceutical firm GlaxoSmithKline in Toronto. Mark is minister at St. Andrew’s Presbyterian Church in Galt. Patrick is the president and CEO of Cambridge Memorial Hospital.

“It’s an easy way to help out,” Howard told the Record. “They do all the work, and I get to sit and then I get to eat cookies.”

Canadian Blood Services says that approximately every minute of every day, someone in Canada needs blood for surgery or for medical treatment. One blood donation can save up to three lives, the agency says.